Allow at least 4 days for the starter to ferment before using.
In a medium bowl, stir together 2 cups of the flour and yeast. Make a well in the middle of the flour/yeast mixture and whisk in the hot water. Continue stirring until the mixture is blended but not completely smooth. It is not necessary to smooth out all the lumps; they will dissolve as the mixture start to ferment. Cover the bowl with a clean towel and let the mixture sit at room temperature. Over the next 24 hours the mixture will rise, become very bubbly and then start to recede.
Days 2 and 3:
Stir the mixture twice, once in the morning and once in the evening to invigorate the yeast and to expel the alcohol. Towards the end of the second day the mixture will start to thin and the surface of the starter will be covered with lots of tiny air bubbles. By the evening of the third day a thin layer of yellow-brown liquid may form on the surface of the starter. It is simply the alcohol given off by the yeast cells as they feed on the carbohydrates in the flour and multiply. Refresh the starter by stirring in the cup of lukewarm water (100F) and the remaining cup of flour. Stir until blended, but do not worry about any small lumps.
The starter is now ready to use, or it may be poured into a sterilized 2 quart glass or ceramic covered crock or casserole, or a glass jar with a non-metal lid and refrigerated.